In a conventional mobile-radio network, such as a GSM network, the switched calls are charged via settlement accounts. Such a settlement account (current account) is assigned to each mobile-radio subscriber. At predetermined time intervals, e.g., monthly, the balance of the respective settlement account is determined and a corresponding bill is sent to the mobile-radio subscriber. The administration of those settlement accounts, the making out of the bills, and the subsequent payment supervision require expensive computer support. Moreover, the integration of the administration of subscriber data and account data necessitates complicated encryption and protection of these data.
As a variant of the above-described charging via settlement accounts, charging via debit accounts is conceivable. Within a mobile-radio network, debit accounts are opened and administered which are assigned to one subscriber profile each. These subscriber profiles are stored on subscriber identity modules (cards) which are bought anonymously and authorize the buyer to use mobile-radio services until the credit is used up. The buyer is thus an anonymous mobile-radio subscriber whose identity is not encoded in the subscriber profile. However, the subscriber profile gives him access to the network and enables him to dispose of the charge credit.